Super Whooper

With spring now well set in, Whooper Swan numbers have dropped quite markedly in recent weeks, as the birds embark on their migration back to Iceland. This winter has seen record counts at WWT Martin Mere (up to 2100 Whoopers on the reserve in January) and on the Ouse Washes (a phenomenal 7271 in February), with good numbers also recorded at WWT Caerlaverock (highest count being of 351 Whoopers on 9th January).

At Martin Mere, numbers held up quite well into mid-March, with 1220 counted on the 18th, but there was a mass exodus over the next few days and by 21st March only 476 swans remained. There was a further decline to 380 on 26th March and 272 on 27th March. These included a bird which had lost its plastic ring (metal ring Z75809 being read by Dave and Estelle Walsh), originally ringed JTP at WWT Caerlaverock as a cygnet back in January 1992, but who's still going strong at 19 years old! Although 198 Whoopers were still present on the Mere on 1st April, just 11 remained yesterday on 7th April.

There was a similar mass migration of Whoopers from Caerlaverock at the start of the 3rd week of March. Counts at the site found that there were still 203 still present on the 17th, but numbers then declined to 180 on the 18th, 80 on the 24th and just 24 remained by the end of the month.

The number of Whooper Swans on the Ouse Washes peaked relatively late in the season, with 7271 counted across the washes on 14th February (a new site record) of which 5286 were on the WWT Welney reserve (also a record, for the reserve). Thereafter numbers dropped quite quickly, to 4887 roosting on the Ouse Washes on 1st March (including 2481 at Welney) and just 55 Whoopers seen at Welney during the day on 29th March. The mild conditions and periods of high atmospheric pressure should have facilitated the swans’ migration this spring.

The whooper swan satellite-tracking project, which aims to describe the migration routes and flight heights of whooper swans in relation to offshore wind farm sites, is being funded by COWRIE (Collaborative Offshore Wind Research Into the Environment). COWRIE is a registered charity, established to improve knowledge and understanding of the potential environmental impacts of offshore wind farm development in UK waters. It supports a range of projects identified by the COWRIE Environment Working Group as areas where further research is needed in relation to offshore wind. Further information can be obtained on the COWRIE website on www.offshorewindfarms.co.uk/Pages/COWRIE/